Tuesday, May 15th, 2007
Dtrace Firefox to get inside the black box
Category: Editorial
John Rice gave a presentation at JavaOne on using Dtrace to instrument Firefox.
The JavaScript VM has long been a black box. We long for monitoring tools that give us access to the runtime as we are used to on the JVM or CLR. We may get there with Silverlight in the future.
Adding Dtrace to Mozilla is far from new, and although it isn’t an easy tweak, enables you to look deep into the innards of the JavaScript engine.
___ OVERLAP TIMES: ___ ______ ELAPSED _____
FILE FUNCTION COUNT AVG(us) SUM(us)
clock.html getSeconds 12 8 104
clock.html padZero 36 7 275
clock.html getMinutes 12 45 548
clock.html getElementById 12 53 640
clock.html getHours 12 59 714
clock.html setTimeout 12 67 807
clock.html startTime 12 1219 14637
Would be handy if he’d make the OpenSolaris binaries available. The toolchain setup and build process looks like it could take a full day.
Of course, if all you’re after is a good and easy to use Javascript profiler, you can use Firebug
its funny months have past and google still shows this post as one of the main points for dtrace and firefox, the world hasn’t come very far in these last few months, you would have thought better java debugging would have amounded by now